A phosphonocrotonic acid derivative is used in synthesis of various compounds from its high functionality, and particularly, triethyl-3-methyl-4-phosphonocrotonate [ethyl (2E,Z)-4-(diethoxyphosphono)-3-methylbuta-2-enoate, hereinafter, also referred to as “TEMPC”] is useful as a raw material of a medicine, an agricultural chemical and an industrial product, and, for example, is useful in synthesis of a compound having a 3-methylpenta-2,4-dienoate residue (the parts surrounded by the solid lines) represented by the following formulae.

It is known that among them, (2E,4E,6E,8E)-3,7-dimethyl-9-(2,6,6-trimethyl-1-cyclohexene-1-yl)nona-2,4,6,8-tetraenoic acid (generic name: tretinoin) is useful as a therapeutic agent for acute promyelocytic leukemia; and ethyl (2E,4E,6E,8E)-9-(4-methoxy-2,3,6-trimethylphenyl)-3,7-dimethylnona-2,4,6,8-tetraenoate (generic name: etretinate) is useful as a therapeutic agent for a family of psoriasis, a family of ichthyosis, and the like; and (2E,4E,6E,10E)-3,7,11,15-tetramethylhexadeca-2,4,6,10,14-pentaenoic acid (generic name: peretinoin) is useful as an inhibitor for liver cell cancer recurrence. TEMPC can be an important raw material for manufacture of these compounds (Patent Document 1).
It is known that TEMPC can be manufactured by Arbuzov reaction in which ethyl 4-bromo-3-methylcrotonate is reacted with triethyl phosphite as illustrated in Scheme 1 described below.

With respect to the reaction, specifically, for example, a method in which a mixture of a cis form and a trans form of ethyl 4-bromo-3-methylcrotonate is reacted with triethyl phosphite at 90° C. for 3 hours, and then distillation is performed to obtain TEMPC as a mixture of a cis/trans form=40/60 (Non-Patent Document 1); a method in which the trans form of ethyl 4-bromo-3-methylcrotonate is reacted with triethyl phosphite at 120° C. for 30 minutes, and then distillation is performed to remove bromoethane, and the reaction mixture is further reacted for 2 hours, and then distillation is performed, whereby a trans form of TEMPC (Non-Patent Document 2) can be obtained; or a method in which a trans form of ethyl 4-bromo-3-methylcrotonate is reacted with triethyl phosphite at 165 to 175° C. for 5 minutes, and then distillation is performed to obtain a trans form of TEMPC (Non-Patent Document 3).